反应详情

温度

65 °C

A solution of 6-bromo-3-methyl-2′,4′,5′,6′-tetrahydrospiro[chroman-2,3′-pyran]-4-one (200 mg, 0.65 mmol) and TiCl4 (864 mg, 4.55 mmol) in anhydrous DCM (8 mL) was heated at 50° C. under microwave for 5 mins. Then bis-trimethylsilylcarbodiimide (360 mg, 1.95 mmol) was added and the mixture was heated at 65° C. for another 1 hr. The reaction mixture was poured into ice-water and extracted with DCM. The combined organic phases were dried over anhydrous Na2SO4, filtered and concentrated to give (E)-N-(6-bromo-3-methyl-2′,4′,5′,6′-tetrahydrospiro[chroman-2,3′-pyran]-4-ylidene)cyanamide (300 mg, crude), which was used in the next step without further purification.

1. extractionextracted with DCM
2. dry with materialThe combined organic phases were dried over anhydrous Na2SO4
3. filtrationfiltered
4. concentrationconcentrated